Rupert Murdoch has not yet taken ownership of the Wall Street Journal, but has already been putting his stamp of authority on the financial newspaper.

Although his company News Corporation's $5bn (£2.5bn) deal to buy WSJ publisher Dow Jones is not expected to complete until December, Mr Murdoch has made several visits to the company's New York headquarters to meet with executives and staff.

Last week Mr Murdoch - who vowed to safeguard the Journal's editorial independence - paid a visit to its headquarters and apparently did a "classic Murdoch number", one source told MediaGuardian.co.uk.

Mr Murdoch is understood to have met with editorial executives on the WSJ and Dow Jones wire service and critiqued the paper's coverage for that particular day. "He basically got out his red felt-tip pen," the insider added.

Mr Murdoch also "spent hours" in meetings with Marcus Brauchli, the paper's managing editor, the Financial Times reported today.

"First of all we don't own the paper yet. We're getting in there and trying to understand it," Peter Chernin, the News Corporation chief operating officer, told the Financial Times.

As part of ownership negotiations before agreeing to buy Dow Jones in August, News Corp made a number of concessions designed to safeguard editorial independence, include the formation of an editorial committee.

News Corp also offered Dow Jones' controlling shareholders the Bancroft family a seat on its board. Mr Murdoch has promised extra investment and wants the Journal to carry more US national news to take on the New York Times, focus more on luxury advertisers, expand the WSJ.com website and possibily dismantle its pay wall.

WSJ.com is one of the few newspaper websites worldwide to operate profitably with a subscription-based business model.

At an investor conference last month, Mr Murdoch said News Corporation had indentified $100m of potential savings at Dow Jones.

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